Transcoding device

Abstract: Known transcoders for compressed video signals comprise a decoder and a coder coupled thereto, between which a data signal is transmitted. Because compressed video signals comprise so-called difference pictures and normal pictures, both the decoder and the coder should have a feedback loop which is utilized in decoding and coding a difference picture and is not utilized in decoding and coding a normal picture. For example, for the purpose of prediction means (motion compensation and motion estimation) present in the feedback loop of the coder, much computation has to be carried out in the coder. The computation required is considerably reduced by concomitantly transmitting one or more information signals in addition to the data signal in a transcoder according to the invention, and complete decoding and complete coding no longer takes place.

Description: A. Background of the invention The invention relates to a transcoding device comprising the features of the preamble of claim 1. Such a transcoding device is known from EP 0 508 597 A2. The data reprocessing means are formed by a part of the ADPCM codec 23(1) or a part of the ADPCM codec 23(2), as shown in figure 1 of this patent application. The demultiplexing means are formed by the Format Transform 21, also shown in figure 1. The data processing means are formed by the other part of the ADPCM codec 23(1) or the other part of the ADPCM codec 23(2) and the multiplexing means are formed by the Format Transform 27. B. Summary of the invention The object of the invention is, inter alia, to provide a transcoding device of the type mentioned in the preamble, in which the computation required is considerably reduced. For this purpose, the transcoding device according to the invention has the characteristic that the data reprocessing means comprise a control input and that the data processing means comprise a control input, both control inputs being coupled to the second output of the demultiplexing means. Via the control inputs, the data reprocessing means and the data processing means are provided with information signals. An embodiment of the transcoding device according to the invention has the characteristic that the information signal comprises a quantization control signal, and in the decoding section the second output of the demultiplexing means comprising a quantization control signal output, the control input of the data reprocessing means comprising a quantization control signal input, and in the coding section the second input of the multiplexing means comprising a quantization control signal input, the control input of the data processing means comprising a quantization control signal input. In this embodiment, the information signal is formed by the quantization control signal which is fed to the data reprocessing means via a control input from the quantization control signal output of the demultiplexing means. Furthermore, the quantization control signal is optionally processed, for example fed via a control unit to a control input of the data processing means and to the quantization control signal input of the multiplexing means. Because the quantization control signal is fed to the coding section, it no longer needs to be derived from the data signal, for which purpose much computation was necessary. A further embodiment of the transcoding device according to the invention has the characteristic that in the decoding section the data reprocessing means comprise decoding means and inverse quantization means, which inverse quantization means are provided with an input coupled to an output of the decoding means and are provided with a control input coupled to the quantization control signal input of the data reprocessing means, and in the coding section the data processing means comprise further quantization means and coding means, which further quantization means are provided with an output coupled to an input of the coding means and are provided with a control input coupled to the quantization control signal input of the data processing means. In accordance with such a transcoding device, the second coded bit stream represents the video signal in accordance with the same standard as the first coded bit stream, but at a lower bit rate. A further embodiment of the transcoding device according to the invention has the characteristic that in the in the decoding section the data reprocessing means comprise inverse transformation means and combining means and prediction means, an input of the inverse transformation means being coupled to an output of the inverse quantization means and an output of the inverse transformation means being coupled to a first input of the combining means and an output of the prediction means being coupled to a second input of the combining means and an output of the combining means being coupled to an input of the prediction means via memory means, and in the coding section the data processing means comprise inverse further quantization means, which inverse further quantization means are provided with an input coupled to the output of the further quantization means and are provided with a control input coupled to the quantization control signal input of the data processing means and the data processing means comprise further transformation means and further combining means and inverse further transformation means and further prediction means, an output of the further transformation means being coupled to an input of the further quantization means and an input of the further transformation means being coupled to an output of the further combining means and an input of the inverse further transformation means being coupled to an output of the inverse further quantization means and an output of the inverse further transformation means being coupled to an input of the further prediction means via further memory means and an output of the further prediction means being coupled to an input of the combining means. In accordance with such a transcoding means, the second coded bit stream represents the video signal in accordance with the same standard, but with one or more modified coding parameters, such as picture size, picture frequency or picture coding procedure, or in accordance with a standard other than the first coded bit stream. A further embodiment of the transcoding device according to the invention has the characteristic that the information signal comprises a vector signal, and in the decoding section the second output of the demultiplexing means comprising a vector signal output, the control input of the data reprocessing means comprising a vector signal control input, and in the coding section the second input of the multiplexing means comprising a vector signal input, the control input of the data processing means comprising a vector signal control input. In this embodiment, the information signal is formed by the vector signal which is fed to the data reprocessing means via a control input from the vector output of the demultiplexing means. Furthermore, the vector signal is optionally processed, for example fed via a translation unit to a control input of the data processing means and to the vector input of the multiplexing means. In this case, the vector signal no longer has to be computed completely in the coding section because it is fed thereto. A further embodiment of the transcoding device according to the invention has the characteristic that the information signal comprises a mode signal, and in the decoding section the second output of the demultiplexing means comprising a mode signal output, the control input of the data reprocessing means comprising a mode signal control input, and in the coding section the second input of the multiplexing means comprising a mode signal input, the control input of the data processing means comprising a mode signal control input. In this embodiment, the information signal is formed by the mode signal which is fed to the data reprocessing means via a control input from the mode output of the demultiplexing means. Furthermore, the mode signal is optionally processed, for example fed via a translation/determination unit to a control input of the data processing means and to the mode input of the multiplexing means. In this case, the mode signal no longer needs to be completely computed in the coding section because it is fed thereto. Obviously, two or more of the embodiments mentioned may be combined in all possible ways. Further favourable embodiments are formulated in the subclaims, that have not been discussed here. In "Picture Conversion for HD Graphics" by Bob Pank, Broadcast Sessions 17th International Television Symposium, 13 June 1991, Montreux, CH, pages 552-558, a transcoder for standards conversion is disclosed. In "A Third Generation Algorithm for Use in High Definition Frame Rate Converters" by M.W.A. David et.al., Broadcast Sessions 18th International Television Symposium, 10 June 1993, Montreux, CH, pages 432-447, in figure 3 on page 441, a Motion Compensated Standards Converter is disclosed. C. References EP 0 508 597 A2. "Picture Conversion for HD Graphics" by Bob Pank, Broadcast Sessions 17th International Television Symposium, 13 June 1991, Montreux, CH, pages 552-558. "A Third Generation Algorithm for Use in High Definition Frame Rate Converters" by M.W.A. David et.al., Broadcast Sessions 18th International Television Symposium, 10 June 1993, Montreux, CH, pages 432-447. D. Exemplary embodiment The invention will be explained in greater detail with reference to an exemplary embodiment shown in the figures. In the latter: Fig. 1 shows a more complex version of a transcoding device according to the invention, and Fig. 2 shows a less complex version of a transcoding device according to the invention. The transcoding device, or transcoder, shown in Fig. 1 is made up of a decoding section 1 and a coding section 21, which are mutually separated by broken line 16. Decoding section 1 comprises demultiplexing means, or demultiplexer, 2 and data reprocessing means 3. Demultiplexer 2 has an input 4 for receiving a first coded bit stream, a first output 5 for coupling to an input of data reprocessing means 3, and a second output which is made up of a vector output 6 for generating a vector signal, a mode output 7 for generating a mode signal, and a quantization control signal output 8 for generating a quantization control signal. Data reprocessing means 3 are provided with decoding means, or VLD (variable length decoder), 9 an input of which is coupled to output 5, and with inverse quantization means 10, an input of which is coupled to an output of VLD 9 and a control input of which is coupled to quantization control signal output 8. Furthermore, data reprocessing means 3 are provided with inverse transformation means 11, an input of which is coupled to an output of inverse quantization means 10, with a combining device 12 (addition circuit), a first input of which is coupled to an output of transformation means 11, with memory means 13, an input of which is coupled to an output of combining device 12, and with prediction means 14, an input of which is coupled to an output of memory means 13 and an output of which is coupled to a second input of combining device 12 and a first control input of which is coupled to vector output 6 and a second control input of which is coupled to mode output 7. The output of combining device 12 is furthermore coupled to an output 15 of data reprocessing means 3. Coding section 21 comprises multiplexing means, or multiplexer, 22 and data processing means 23. Multiplexer 22 has a first input 25 for coupling to an output of data processing means 23, a second input which is made up of a vector input 26 for receiving a vector signal, a mode input 27 for receiving a mode signal, and a quantization control signal input 28 for receiving a quantization control signal, and an output 24 for generating a second coded bit stream. Data processing means 23 are provided with quantization means 32, and with coding means, or VLC (variable length coder), 33 an input of which is coupled to an output of quantization means 32 and an output of which is coupled to input 25. Furthermore, data processing means 23 are provided with a combining device 30 (subtraction circuit), a first input of which is coupled to an input 29 of data processing means 23, with transformation means 31, an input of which is coupled to an output of combining device 30 and an output of which is coupled to an input of quantization means 32, with inverse quantization means 34, an input of which is coupled to the output of quantization means 32, with inverse transformation means 35, an input of which is coupled to an output of inverse quantization means 34, with combining circuit 36 (addition circuit), a first input of which is coupled to an output of inverse transformation means 35, with memory means 37, an input of which is coupled to an output of combining device 36, and with prediction means 38, an input of which is coupled to an output of memory means 37 and an output of which is coupled to a second input of combining device 30 and to a second input of combining device 36 and a first control input of which is coupled to vector input 26 and a second control input of which is coupled to mode input 27. Output 15 and input 29 are mutually connected via coupling 39, which coupling is, in its simplest form, a through connection, and, in a more complex form, is, for example, a post processor known to the person skilled in the art or, for example, is a temporal and/or spatial converter known to the person skilled in the art. Vector output 6 and vector input 26 are mutually connected via a further coupling 40 and mode output 7 and mode input 27 are mutually connected via a further coupling 41. A simplest form of further coupling 40 is a through connection, whereas a more complex form is, for example, a translation unit 40 known to the person skilled in the art, the vector signal of the vector output 6 being converted into another vector signal for vector input 26 in order to make it possible, for example, to translate from one standard into another standard, it sometimes being necessary to adjust the accuracy and/or range of the vector information. There is also the possibility that different vector signals have to be combined to form one vector signal. A simplest form of further coupling 41 is a through connection, whereas a more complex form is, for example, a translation/determination unit 41 known to the person skilled in the art, the mode signal of mode output 7 being converted into another mode signal for mode input 27 in order to make it possible, for example, to translate one standard into another standard, it sometimes being necessary to redetermine the mode signal, as has to be done, correspondingly, in separate encoders. If the temporal and/or spatial converter 39 is used vector information and/or mode information is economized on to a greater or lesser extent per interval of time, the translation unit and translation/determination unit then having to be adjusted by converter 39 via connections not shown in Fig. 1. Control unit 17, which could also be regarded as a further coupling, is provided with an input 18, coupled to quantization control signal output 8, for receiving the quantization control signal, with an output 19, coupled to output 24, for receiving the second coded bit stream, and with an output 20, coupled to input 28 and to a control input of quantization means 32 and to a control input of inverse quantization means 34, for supplying a further quantization control signal. Control unit 17 furthermore generally has a preset input, not shown in Fig. 1, for setting an adjustable ratio, the so-called input/output bit rate. The operation of the transcoder shown in Fig. 1 is as follows. Multiplexer 2 receives, at input 4, the first coded bit stream, which is split up into a signal which is fed via output 5 to VLD 9, into a vector signal which is fed via vector output 6 to the first control input of prediction means 14 and to further coupling (translation unit) 40, into a mode signal which is fed via mode output 7 to the second control input of prediction means 14 and to further coupling (translation/determination unit) 41, and into a quantization control signal which is fed via quantization output 8 to the control input of inverse quantization means 10 and to input 18 of control unit 17. VLD 9 performs a decoding, for example on the basis of a table, after which inverse quantization means 10 perform an inverse quantization and inverse transformation means 11 perform an inverse transformation, for example an inverse discrete cosine transformation. In this way, a data signal is obtained which is the difference between a particular group of picture elements, or pixels, of a particular picture and a particular group of pixels of a picture preceding it. With the aid of the feedback loop containing therein the prediction means 14 (motion compensation means) and the memory means 13, the particular group of pixels of the particular picture then appears as a data signal at output 15. If account is taken of movements in the picture content of consecutive pictures during coding, this is compensated for by prediction means 14 (motion compensation means) in response to the vector signal and/or the mode signal. From output 15, said data signal flows (possibly via the temporal and/or spatial converter 39 to economize on vector information and/or mode information) to input 29, a predetermined number of bits thus forming a picture element or pixel. Assuming that the capacity of memory means 37 is unoccupied, a first group of pixels reaches, via combining device 30, the transformation means 31, which perform, for example, a discrete cosine transformation on the group of pixels, the associated coefficient being determined for each frequency component. The quantization means 32 quantize the signal obtained. The quantized signal is then coded by VLC 33, for example on the basis of a table with which new code words are generated which, on average, have a shorter length than the incoming words, and is fed to input 25 of multiplexer 22. This transformed, quantized and coded first group of pixels consequently forms the first section of the coded signal. After being transformed and quantized, the first group of pixels is inversely quantized by inverse quantization means 34 and inversely transformed by inverse transformation means 35, and stored at a first location in memory means 37 via combining device 36. A second group of pixels traverses the same route as the first group of pixels, undergoes the same operations and is stored at a second location in memory means 37, etc., until all the groups of pixels of one complete picture (the first picture) have been stored. The first group of pixels of the subsequent (second) picture is then presented to input 29. In this connection, it is conceivable that prediction means 38 (motion estimation means) make a prediction (estimation), on the basis of a connection to input 29 not shown in Fig. 1, of a possible movement in the picture in order to improve the quality of the coding. At the same time, (the prediction of) the first group of pixels of the preceding (first) picture is fed via prediction means 38 to the first group of pixels of the (second) picture to be coded via combining device 30. Because the difference between the first group of pixels of the second picture and the first group of pixels of the first picture is then presented to data processing means 23, the coding proceeds appreciably more efficiently. Taking account of any movements in the picture content of consecutive pictures by means of the prediction means 38 increases the efficiency still further. Instead of vectors, other prediction parameters determined on the basis of other prediction methods can, of course, be transmitted. What is described above is the operation of the transcoder in regard to a first layer which is shown in Fig. 1 and which is built up around data reprocessing means 3 and data processing means 23. The operation in regard to a second layer, which is not shown in Fig. 1, for the purpose of pyramidal or layered coding and decoding and built up around further reprocessing means and further data processing means is, in principle, identical. According to the transcoder shown in Fig. 1, the second coded bit stream represents the video signal in accordance with the same standard as the first coded bit stream, but with one or more modified coding parameters, such as picture size, picture frequency and picture coding procedure, or in accordance with a standard other than the first coded bit stream. In the case of conventional transcoders, there is no input 18 in control unit 17 for receiving the quantization control signal from quantization control signal output 8. Furthermore, the further couplings 40 and 41 are not present in such cases, and each information signal (quantization control signal, vector signal, mode signal) is recomputed in the coding section, the data signal to be transported via coupling 39 representing the video signal per se in uncoded form. The computation takes place on the basis of said data signal. Owing to the passing of information signals from the decoding section 1 to the coding section 21, the latter no longer have to be computed in the coding section 21, which thus economizes on computation. If the transcoder according to the invention is regarded as a linear system, a simplified version of control unit 17 operates as follows. Because it is approximately true that (decoding section quantization)/(coding section quantization) = (outgoing data)/(incoming data), that (incoming data + incoming information)/(outgoing data + outgoing information) = (adjustable ratio) and that (incoming information) = outgoing information), all the parameters being known or having to be set except (coding section quantization) and (outgoing data), control unit computes these two unknown parameters on the basis of the said equations, after which the coding section is fed a certain quantization control signal. A subsequent (partial) coding is performed with the latter and this leads to new outgoing data, which are fed back to control unit 17. This diagnoses a certain error, which results in further adjustment in the computation of the subsequent quantization control signal. The transcoding device, or transcoder, shown in Fig. 2 is made up of a decoding section 1 and a coding section 21, mutually separated by broken line 16. Decoding section 1 comprises demultiplexing means, or demultiplexer, 2 and data reprocessing means 3. Demultiplexer 2 has an input 4 for receiving a first coded bit stream, a first output 5 for coupling to an input of data reprocessing means 3, and a second output which is made up of a vector output 6 for generating a vector signal, a mode output 7 for generating a mode signal, and a quantization control signal output 8 for generating a quantization control signal. Data reprocessing means 3 are provided with decoding means, or VLD (variable length decoder), 9 an input of which is coupled to output 5, and with inverse quantization means 10, an input of which is coupled to an output of VLD 9 and a control input of which is coupled to quantization control signal output 8 and an output of which is coupled to an output 15 of data reprocessing means 3. Coding section 21 comprises multiplexing means, or multiplexer, 22 and data processing means 23. Multiplexer 22 has a first input 25 for coupling to an output of data processing means 23, a second input which is made up of a vector input 26 for receiving a vector signal, a mode input 27 for receiving a mode signal, and a quantization control signal input 28 for receiving a quantization control signal, and an output 24 for generating a second coded bit stream. Data processing means 23 are provided with quantization means 32, an input of which is coupled to an input 29 of data processing means 32 and a control input of which is coupled to quantization control signal input 28, and with coding means, or VLC (variable length coder), 33 an input of which is coupled to an output of quantization means 32 and an output of which is coupled to input 25. Output 15 and input 29 are mutually connected via a coupling 39, which is not shown in Fig. 2, which coupling is in this case a through connection. Vector output 6 and vector input 26 are mutually connected via a further coupling 40, which is not shown in Fig. 2, and mode output 7 and mode input 27 are mutually connected via a further coupling 41. In this case, further coupling 40 is a through connection, whereas further coupling 41 is a translation/determination unit 41 known to the person skilled in the art, the mode signal of mode output 7 being converted into another mode signal for mode input 27 because, even if no translation is necessary from one standard to another standard, it is nevertheless sometimes necessary to redetermine the mode signal, as occurs, correspondingly, in separate encoders, all this being dependent on the data processing means 23. Control unit 17, which could also be regarded as a further coupling, is provided with an input 18, coupled to the quantization control signal output 8, for receiving the quantization control signal, with an input 19, coupled to output 24, for receiving the second coded bit stream, and with an output 20, coupled to the quantization control signal input 28 and to a control input of quantization means 32, for supplying a further quantization control signal. Control unit 17 furthermore generally has a preset input, not shown in Fig. 2, for setting an adjustable ratio, the so-called input/output bit rate. The operation of the transcoder shown in Fig. 2 is as follows. Multiplexer 2 receives, at input 4, the first coded bit stream, which is split up into a signal which is fed via output 5 to VLD 9, into a vector signal which is fed via vector output 6 to the coding section 21, into a mode signal which is fed via mode output 7 to further coupling (translation/determination unit) 41 and into a quantization control signal which is fed via quantization output 8 to the control input of inverse quantization means 10 and to input 18 of control unit 17. VLD 9 performs a decoding, for example on the basis of a table, after which inverse quantization means 10 perform an inverse quantization. In this way, a data signal is obtained at output 15 which is the difference between a particular group of picture elements, or pixels, of a particular picture and a particular group of pixels of a picture preceding it. Said data signal is therefore still in a certain transformation domain as a consequence of the lack of inverse transformation means and thus represents a video signal which is still to some extent coded. From output 15, said data signal flows to input 29. The quantization means 32 quantize said data signal. The quantized signal is then coded by VLC 33, for example on the basis of a table with which new code words are generated which have, on average, a shorter length than the incoming words, and is fed to input 25 of multiplexer 22. This quantized and coded signal is then converted, together with the quantization control signal computed by control unit 17, the unmodified vector signal and any adjusted mode signal, into the second coded bit stream by multiplexer 22. According to this transcoder, the second coded bit stream represents the video signal in accordance with the same standard as the first coded bit stream, but at a lower bit rate. Compared with the transcoder shown in Fig. 1, further coupling 40, or translation unit 40, is lacking in the transcoder shown in Fig. 2 because the vector signal from vector output 6 does not need to be converted into another vector signal for vector input 26 as a consequence of the fact that no translation from one standard into the other standard is necessary, and no adjustment of the accuracy and/or range of the vector information is necessary, and that no vector signals need to be combined to form one vector signal. Further coupling 41, or translation/determination unit 41, is, however, still present in the transcoder shown in Fig. 2 because, while the same standard has been retained, data processing means 23 may nevertheless make a mode change necessary, in which case they drive translation/determination unit 41, via a connection which is not shown in Fig. 2.

Claims: Transcoding device suitable for compressed/coded video signals comprising a decoding section (1) which is provided with data reprocessing means (3) having an output (15) for generating a data signal, and demultiplexing means (2) having an input (4) for receiving as an input signal of the transcoding device a first coded bit stream and having a first output (5) coupled to an input of the data reprocessing means (3) and having a second output (6;7;8) for generating at least one information signal including one of a quantization control signal, a mode signal and a vector signal, a coding section (21) which is provided with data processing means (23) having an input (29) coupled to the output (15) of the data reprocessing means (3) for receiving the data signal, and multiplexing means (22) having a first input (25) coupled to an output of the data processing means (23) and having a second input (26;27;28) coupled to the second output (6;7;8) of the demultiplexing means (2) for receiving said at least one information signal and having an output (24) for generating and outputting a second coded bit stream, characterized in that the data reprocessing means (3) comprise a control input and that the data processing means (23) comprise a control input, both control inputs being coupled to the second output (6;7;8) of the demultiplexing means (2) in order to perform the reprocessing and processing operation, respectively, using said information signal. Transcoding device according to Claim 1, characterized in that the information signal comprises the quantization control signal, and in the decoding section (1) the second output (6;7;8) of the demultiplexing means (2) comprising a quantization control signal output (8), the control input of the data reprocessing means (3) comprising a quantization control signal input, and in the coding section (21) the second input (26;27;29) of the multiplexing means (22) comprising a quantization control signal input (8), the control input of the data processing means (23) comprising a quantization control signal input. Transcoding device according to Claim 2, characterized in that in the decoding section (1) the data reprocessing means (3) comprise decoding means (9) and inverse quantization means (10), which inverse quantization means (10) are provided with an input coupled to an output of the decoding means (9) and are provided with a control input coupled to the quantization control signal input of the data reprocessing means (3), and in the coding section (21) the data processing means (23) comprise further quantization means (32) and coding means (33), which further quantization (32) means are provided with an output coupled to an input of the coding means (33) and are provided with a control input coupled to the quantization control signal input of the data processing means (23). Transcoding device according to Claim 3, characterized in that in the in the decoding section (1) the data reprocessing means (3) comprise inverse transformation means (11) and combining means (12) and prediction means (14), an input of the inverse transformation means (11) being coupled to an output of the inverse quantization means (10) and an output of the inverse transformation means (11) being coupled to a first input of the combining means (12) and an output of the prediction means (14) being coupled to a second input of the combining means (12) and an output of the combining means (12) being coupled to an input of the prediction means (14) via memory means (13), and in the coding section (21) the data processing means (23) comprise inverse further quantization means (34), which inverse further quantization means (34) are provided with an input coupled to the output of the further quantization means (32) and are provided with a control input coupled to the quantization control signal input of the data processing means (23) and the data processing means (23) comprise further transformation means (31) and further combining means (30) and inverse further transformation means (35) and further prediction means (38), an output of the further transformation means (31) being coupled to an input of the further quantization means (32) and an input of the further transformation means (31) being coupled to an output of the further combining means (30) and an input of the inverse further transformation means (35) being coupled to an output of the inverse further quantization means (34) and an output of the inverse further transformation (35) means being coupled to an input of the further prediction means (38) via further memory means (37) and an output of the further prediction means (38) being coupled to an input of the combining means (30). Transcoding device according to Claim 4, characterized in that the information signal comprises the vector signal, and in the decoding section (1) the second output (6;7;8) of the demultiplexing means (2) comprising a vector signal output (6), the control input of the data reprocessing means (3) comprising a vector signal control input which is coupled to a vector signal control input of the prediction means (14), and in the coding section (21) the second input (26;27;28) of the multiplexing means (22) comprising a vector signal input (26), the control input of the data processing means (23) comprising a vector signal control input which is coupled to a vector signal control input of the further prediction means (38). Transcoding device according to Claim 4 or 5, characterized in that the information signal comprises the mode signal, and in the decoding section (1) the second output (6;7;8) of the demultiplexing means (2) comprising a mode signal output (7), the control input of the data reprocessing means (3) comprising a mode signal control input which is coupled to a mode signal control input of the prediction means (14), and in the coding section (1) the second input (26;27;28) of the multiplexing means (22) comprising a mode signal input (27), the control input of the data processing means (23) comprising a mode signal control input which is coupled to a mode signal control input of the further prediction means (38). Transcoding device according to Claim 1, characterized in that the information signal comprises the vector signal, and in the decoding section (1) the second output (6;7;8) of the demultiplexing means (2) comprising a vector signal output (6), the control input of the data reprocessing means (3) comprising a vector signal control input, and in the coding section (21) the second input (26;27;28) of the multiplexing means (2) comprising a vector signal input (26), the control input of the data processing means (23) comprising a vector signal control input. Transcoding device according to Claim 7, characterized in that in the decoding section (1) the data reprocessing means (3) comprise decoding means (9) and inverse quantization means (10) and inverse transformation means (11) and combining means (12) and prediction means (14), an input of the inverse quantization means (10) being coupled to an output of the decoding means (9) and an output of the inverse quantization means (10) being coupled to an input of the inverse transformation means (11) and an output of the inverse transformation means (11) being coupled to a first input of the combining means (12) and an output of the prediction means (14) being coupled to a second input of the combining means (12) and an output of the combining means (12) being coupled to an input of the prediction means (14) via memory means (13), which prediction means (14) are provided with a vector signal control input coupled to the vector signal control input of the data reprocessing means (3), and in the coding section (21) the data processing means (23) comprise further combining means (30) and further transformation means (31) and further quantization means (32) and coding means (33) and inverse further quantization means (34) and inverse further transformation means (35) and further prediction means (38), an output of the further transformation means (31) being coupled to an input of the further quantization means (32) and an input of the further transformation means (31) being coupled to an output of the further combining means (30) and an output of the further quantization means (32) being coupled to an input of the coding means (33) and the output of the further quantization means (32) being coupled to an input of the inverse further quantization means (34) and an input of the inverse further transformation means (35) being coupled to an output of the inverse further quantization means (34) and an output of the inverse further transformation means (35) being coupled to an input of the further prediction means (38) via further memory means (37) and an output of the further prediction means (38) being coupled to an input of the combining means (30), which further prediction means (38) are provided with a vector signal control input coupled to the vector signal control input of the data processing means (23). Transcoding device according to Claim 8, characterized in that the information signal comprises the mode signal, and in the decoding section (1) the second output (6;7;8) of the demultiplexing means (2) comprising a mode signal output (7), the control input of the data reprocessing means (3) comprising a mode signal control input which is coupled to a mode signal control input of the prediction means (14), and in the coding section (21) the second input (26;27;28) of the multiplexing means (2) comprising a mode signal input (7), the control input of the data processing means (23) comprising a mode signal control input which is coupled to a mode signal control input of the further prediction means (38). Transcoding device according to Claim 1, characterized in that the information signal comprises the mode signal, and in the decoding section (1) the second output (6;7;8) of the demultiplexing means (2) comprising a mode signal output (7), the control input of the data reprocessing means (3) comprising a mode signal control input, and in the coding section (21) the second input (26;27;28) of the multiplexing means (2) comprising a mode signal input (7), the control input of the data processing means (23) comprising a mode signal control input. Transcoding device according to Claim 10, characterized in that in the decoding section (1) the data reprocessing means (3) comprise decoding means (9) and inverse quantization means (10) and inverse transformation means (11) and combining means (12) and prediction means (14), an input of the inverse quantization means (10) being coupled to an output of the decoding means (9) and an output of the inverse quantization means (10) being coupled to an input of the inverse transformation means (11) and an output of the inverse transformation means (11) being coupled to a first input of the combining means (12) and an output of the prediction means (14) being coupled to a second input of the combining means (12) and an output of the combining means (12) being coupled to an input of the prediction means (14) via memory means (13), which prediction means (14) are provided with a mode signal control input coupled to the mode signal control input of the data reprocessing means (3), and in the coding section (21) the data processing means (23) comprise further combining means (30) and further transformation means (31) and further quantization means (32) and coding means (33) and inverse further quantization means (34) and inverse further transformation means (35) and further prediction means (38), an output of the further transformation means (31) being coupled to an input of the further quantization means (32) and an input of the further transformation means (31) being coupled to an output of the further combining means (30) and an output of the further quantization means (32) being coupled to an input of the coding means (33) and the output of the further quantization means (32) being coupled to an input of the inverse further quantization means (34) and an input of the inverse further transformation means (35) being coupled to an output of the inverse further quantization means (34) and an output of the inverse further transformation means (35) being coupled to an input of the further prediction means (38) via further memory means (37) and an output of the further prediction means (38) being coupled to an input of the combining means (30), which further prediction means (38) are provided with a mode signal control input coupled to the mode signal control input of the data processing means (23). Transcoding device according to any one of Claims 2-6, characterized in that the transcoding device comprises a control unit (17), a first input (18) of the control unit (17) being coupled to the quantization control signal output (8) of the demultiplexing means (2), a second input (19) of the control unit (17) being coupled to the output (24) of the multiplexing means (22), and an output (20) of the control unit (17) being coupled to the quantization control signal input of the data processing means (23). Transcoding device according to any one of Claims 5, 7, 8 and 9, characterized in that the transcoding device comprises a translation unit (40), an input of the translation unit (40) being coupled to the vector signal output (6) of the demultiplexing means (2), and an output of the translation unit (40) being coupled to the vector signal control input (26) of the data processing means (23) and to the vector signal input (26) of the multiplexing means (22). Transcoding device according to any one of Claims 6, 9, 10 and 11, characterized in that the transcoding device comprises a translation/determination unit (41), an input of the translation/determination unit (41) being coupled to the mode signal output (7) of the demultiplexing means (2), and an output of the translation/determination unit (41) being coupled to the mode signal control input of the data processing means (23) and to the mode signal input (27) of the multiplexing means (22).

Inventors: KOPPELMANS JOHANNES FRANSISCUS, KOSTER ARIAN, SCHINKEL DOLF ALBERT, KOPPELMANS, JOHANNES FRANSISCUS A., KOSTER, ARIAN, SCHINKEL, DOLF ALBERT
Applicants: KONINKL KPN NV, KONINKLIJKE KPN N.V.
Application year: 1994
Main classification: H04N7
IPC codes: H04N7, H03M7, H04N11